Ongoing efforts have been directed to making blow molding compositions, particularly for bottles. The goal is for the composition to be made economically and efficiently, but also to provide a composition with the right balance of properties, e.g., strength, stiffness, as well as good processability.
Higher density polyethylene blow molding compositions typically show poor environmental stress crack resistance (ESCR). ESCR is a measure of mechanical failure. Consequently, higher density polyethylene compositions have not been used for blow molding applications, especially for bottles where a high resistance to cracking, i.e. high ESCR, is desired or required. However, higher density compositions are preferred to obtain the desired mechanical properties such as bottle rigidity.
There is a need, therefore, for higher density polyethylene compositions that exhibit good ESCR as well as good mechanical strength properties suitable for blow molding applications, including bottles.